One of the most persistent and troublesome problems arising during modern fabric laundering operations is the tendency of some colored fabrics to release dye into the laundering solutions. The dye is then transferred onto other fabrics being washed therewith.
One way of overcoming this problem would be to complex or adsorb the fugitive dyes washed out of dyed fabrics before they have the opportunity to become attached to other articles in the wash.
Polymers have been used within detergent compositions to inhibit dye transfer, such as disclosed in EP-A-102 923, DE-A-2 814 329, FR-A-2 144 721 and EP-265 257.
Copending EP Patent Application 92202168.8 describes dye transfer inhibiting compositions comprising polyamine N-oxides containing polymers.
Another way of overcoming the problem of dye transfer would be to bleach the fugitive dyes washed out of dyed fabrics before they have the opportunity to become attached to other articles in the wash.
Suspended or solubilized dyes can to some degree be oxidized in solution by employing known bleaching agents.
GB 2 101 167 describes a stable liquid bleaching composition containing a hydrogen peroxide precursor which is activated to yield hydrogen peroxide on dilution.
However it is important at the same time not to bleach the dyes actually remaining on the fabrics, that is, not to cause color damage.
U.S. Patent 4,077,768 describes a process for inhibiting dye transfer by the use of an oxidizing bleaching agent together with a catalytic compound such as iron porphins.
Copending EP Patent Application 91202655.6 filed October 9, 1991, relates to dye transfer inhibiting compositions comprising an enzymatic system capable of generating hydrogen peroxide and porphin catalysts.
It has now been surprisingly found that polyamine N-oxide polymers and metallo-catalysts provide superior and synergistic dye transfer inhibiting properties compared to the catalyst- or polymers-system taken alone. This finding allows to formulate compositions which exhibit excellent dye transfer inhibiting properties with low level of catalysts, which in turn, reduces the problem of catalyst deposition onto fabrics.
According to another embodiment of this invention a process is also provided for laundering operations involving colored fabrics.